At 4 foot 10, Raegan Brierton makes a pretty convincing three-year-old. As the pigtailed Boo in the touring production of Monsters, Inc. , she's the only human face on a rink full of multilimbed ogres and nine-foot beasts. "Everything's larger than life and super-sized," she says. "It doesn't matter where you're sitting, because you see everything."

The two-hour show mirrors Disney's 2001 hit movie about Boo and her uninvited visit to Monstropolis, a city populated by monsters that believe a child's touch is toxic -- until blue-furred Sulley and one-eyed sidekick Mike find out otherwise. "[Boo] goes through all these adventures with her two friend monsters," says the 25-year-old Brierton. "Basically, the challenge is letting people know that I'm still a child."

Brierton pulls off Boo's antics with scrunched-up facial expressions, infectious giggles, and gimme -- it's mine! hissy fits. In one scene, she finds a teddy bear on her bed. "Mikey takes it away from her, and that starts a tantrum, because they won't let her play with it," she says. Brierton relates to that determination. As a third-grader, she was drawn to competitive ice skating after watching the 1988 Olympics. An accomplished gymnast, Brierton asked her parents if she could take to the ice. For the next six years, she competed as an amateur throughout the Midwest. "I think I was at that age where I was looking for something I wanted to do," she says. "I was not a big girl, so a lot of sports were out, and skating really appealed to me."

By the time she was 20, Brierton had won a spot with Disney on Ice, taking roles in The Little Mermaid, Toy Story 2, and Jungle Adventures. This season, she says, she's content to play a precocious toddler with a madness for monsters. "It lets me let go of all my adult worries and concerns."